package com.hit.basmath.learn.queue_stack;

import java.util.Arrays;

/**
 * 279. Perfect Squares
 * <p>
 * Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n.
 * <p>
 * Example 1:
 * <p>
 * Input: n = 12
 * Output: 3
 * Explanation: 12 = 4 + 4 + 4.
 * <p>
 * Example 2:
 * <p>
 * Input: n = 13
 * Output: 2
 * Explanation: 13 = 4 + 9.
 */
public class _279 {
    public int numSquares(int n) {
        int[] dp = new int[n + 1];
        Arrays.fill(dp, Integer.MAX_VALUE);
        dp[0] = 0;
        for (int i = 1; i <= n; ++i) {
            int min = Integer.MAX_VALUE;
            int j = 1;
            while (i - j * j >= 0) {
                min = Math.min(min, dp[i - j * j] + 1);
                ++j;
            }
            dp[i] = min;
        }
        return dp[n];
    }
}
